harvey_2023
===========

A\. H\. Harvey, E\. W\. Lemmon, D\. O\. Ortiz Vega, K\. R\. Hall and J\. C\. Holste, "An Equation of State for the Thermodynamic Properties of Helium", NIST Interagency Report 8474 \(2023\)

`Source record <https://github.com/LupoLab/optmat/blob/main/src/optmat/data/sources/harvey_2023.toml>`__ · :doc:`Catalogue </the-data/sources>` · :doc:`Review register </register>`

DOI: `10\.6028/nist\.ir\.8474 <https://doi.org/10.6028/nist.ir.8474>`__

**Source kind:** fit

**Recorded technique:** A Helmholtz\-energy equation of state for helium\-4, 2\.1768\-1500 K and pressures to 2000 MPa, fitted to measured and ab initio thermodynamic data\. It stands here for the equation CoolProp names OrtizVega\-JPCRD\-2019, which is not in hand\.

**Materials in structured entries:** None recorded.

**Dataset quantities:** None recorded.

**Contents:** 0 datasets; 0 formulas.

Curation notes
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Identity VALIDATED by the library\. Pages are the report's pdf pages\.

IDEAL GAS AND CONSTANTS \(Table 1, p\. 8; Eq\. 3, p\. 9\)\: M = 4\.002602 g/mol and R = 8\.314472 J/\(mol K\), which 'should be used' with the equation; the ideal\-gas part is the monatomic gas's, c\_p0 = \(5/2\) R\. Range 2\.1768\-1500 K, 2000 MPa \(p\. 21\)\.

AGAINST COOLPROP 8\.0\.0 \(reference key OrtizVega\-JPCRD\-2019, computed 2026\-09\-30\)\: the same M and c\_p0 = \(5/2\) R with R = 8\.3144598 J/\(mol K\), 1\.47e\-6 below the report's\. The report is taken here as the published form of CoolProp's equation\: CoolProp's own bibliography lists that one as unpublished \(D\. O\. Ortiz\-Vega, K\. R\. Hall, J\. C\. Holste, V\. D\. Arp, A\. H\. Harvey and E\. W\. Lemmon, 'Equation of state for Helium\-4', 2019\)\. Only the ideal part and M are used from it, where the two agree\. optmat's c\_p0 is \(5/2\) R with CODATA's R \(optmat\.gas\.transport\)\.

**Recorded bibliographic identity status:** VALIDATED. This concerns identification of the source; it does not establish the scientific correctness of its contents.

Datasets
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No datasets are recorded.

Formulas
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No formulas are recorded.

Corrections
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No dataset errata are recorded in this source record.

Formula corrections, where recorded, appear with their formulas above. Curation notes may also discuss corrections or unresolved interpretation. Consult the :doc:`review register </register>` for the checks and decisions.